The present invention relates to a motor-driven film winder for use with cameras which has a film-winding motor that can be utilized for attaching the film winder to and detaching the film winder from the camera.
Motor-driven film winders are normally attached to cameras by threading and tightening a mounting screw through the film winder into the tripod screw hole in the bottom of the camera. As the film winder is mounted on the camera, the drive coupler of the film winder is mechanically connected to the driven coupler of the camera and at the same time the film winder and the camera are electrically connected. In use, an exposure end signal and a film winding completion signal (or a shutter charge signal) are transmitted from the camera to the film winder to control the energization and de-energization of the motor in the motor-driven film winder.
The conventional motor-driven film winders are attached to and detached from the cameras by manually tightening and loosening the mounting screws. Therefore, it is tedious and timing-consuming to mount and remove the film winders. The mounting screws are liable to be tightened with varying forces. If the tightening force is weak, then the film winder tends to get loose gradually from the camera until the electric connection between the camera and the film winder is rendered unstable or otherwise impaired, resulting in a film winding failure.